Vacuum Distillation Setup on a Budget

[GiTS]

I've got a simple vacuum distillation setup but no vacuum source. I need to pull 10 Torr. I also don't want to break the bank. I'm considering using an air compressor and aspirator, but I don't know if it will be adequate.

this is the http://www.overstock.com/Auto-Parts...=123620&fp=F&ci_src=14110944&ci_sku=11183135"

 

[Q_Goest]

Hi GiTS. I really don't think that will work. Even if modified to reduce piston ring leakage, it's only a single stage, so I doubt it would get below ~2 psia assuming it was properly modified. But modifying that is going to be more expensive than just getting a real vacuum pump.

Try ebay or Craigslist. A used one can be picked up for about $50 from what I've seen.

 

[GiTS]

I don't want to turn the compressor into a vac. I want to hook the output up to a compressed air powered aspirator. But I don't know how much horsepower I need to get the aspirator to pull 10 Torr.

 

[negitron]

I should think the specs of the aspirator would tell you.

 

[Q_Goest]

Oh, yes... sorry. That air compressor certainly has enough flow and pressure to drive the smaller ones found here: http://www.mcmaster.com/#vacuum-pumps/=2t08si

 

[negitron]

Incidentally, 10 Torr is well within the capabilities of a single-stage rotary vane pump, of the type used by HVAC repairmen. I have one I use for various nefarious vacuum-related experiments.

 

[GiTS]

thanks for the tip. I think this might be perfect
http://cgi.ebay.com/Rotary-Vane-Vacuum-Pump-29%22Hg-3-CFM-1%2f4-HP-AC-HVAC-Tool_W0QQitemZ390068911886QQcmdZViewItem

 

[MATLABdude]

29 in-Hg of vacuum works out to 736 Torr below atmospheric (which is nominally 760, depending on where you live / work).

May want to make sure your glassware can handle that without imploding (assuming that you in fact reach the ultimate pressure of the pump).

 

[fleem]

Lots of good (and cheap) stuff at harbor Freight:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92474
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=39522
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=66466
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=66467
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96677
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=98076

 

[negitron]

You need one more like this one:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390066833029